By the very nature of the utilization of liquid substances such as liquid hydrocarbon fuels, it is frequently necessary to transfer a liquid fuel from a first storage vessel in which it is contained to a second storage vessel. One particular instance in which it is necessary to so transfer a liquid fuel is in the case of re-fueling an automobile during a racing event.
One particular class of automobile racing is where competing vehicles must travel an extended period of time to cover the pre-determined distance of the race. Such automobile races have been known since the advent of the automobile itself, and current NASCAR and other events include such races as the Indianapolis 500, the California 500, the Virginia 500, New England 300, to name but a few. Such automobile races typically require drivers and their cars to travel hundreds of miles from start to finish. Quite often, such races are carried out on a track, which may be circular, oval, or which may trace out a serpentine course.
Since the fuel-carrying capacity of the race car is limited by the rules of racing to be of specific volume, and the capacity of such tanks is not sufficient to enable the racer to complete the entire race on a single tank load of fuel, it is a general requirement of modern automobile racing that drivers must stop their vehicles periodically to have their tanks re-charged with fuel. Since the nature of racing is such that the first racer to cross the finish line is generally declared the winner, the amount of time used for the combined re-fueling operations becomes a significant factor in determining the outcome of any given race. Hence, it is essential from the standpoint of the racing team that the time utilized in re-fueling and other pit-stop operations is kept to an absolute minimum.
The current state-of-the-art method for re-fueling a racing vehicle in a circle-track application is for the racer to pull their car into an area known to those skilled in the art as the “pit-stop” for servicing. As is customary, the on-board fuel tank of a racing vehicle includes an inlet conduit through which fuel is admitted to the tank during re-fueling. There is also an exit conduit through which fuel is exited from the fuel tank and delivered by means of a fuel pump to the engine. There is also a cap or other means of sealing the inlet conduit from the surrounding environment after a re-fueling of the vehicle is complete. There is a headspace volume above the liquid level of the fuel in the tank. Initially, when the tank is full, the headspace volume is at its minimum. As fuel is consumed, the headspace volume increases, and reaches its maximum when all of the liquid fuel formerly contained in the tank has been consumed.
It is through the inlet conduit of the fuel tank that fuel is admitted during a pit-stop re-fueling operation. During a re-fueling, a member of the pit crew carries a large funnel-shaped vessel (the “recharging tank”) which is full of a motor fuel, such as a gasoline. The recharging tank includes a fitting on its lower extremity which is complementary to that on the end of the inlet conduit on the fuel tank that receives fuel. After the racer's vehicle comes to a stop, the pit crew will remove the cap from the fuel tank inlet conduit. Then, the fitting on the recharging tank is mated to the fitting on the inlet conduit to form a sealed conduit through which fuel may pass from the recharging tank to the on-board fuel tank of the race car. A valve disposed on the recharging tank is opened, and fuel contained within the recharging tank is caused to flow, by the force of gravity, from the recharging tank into the on-board fuel tank of the racing vehicle.
The re-fueling of a racing vehicle is undertaken in as quick a time as seems possible, and with minimizing the losses of fuel during the operation. However, one of the disadvantages of prior art re-fueling methods is that large volumes of gasoline were spilled onto the pavement and portions of the vehicle being re-fueled. A typical volume of fuel lost by spillage in re-fueling operations during the course of a race may be several gallons of fuel, which losses occur primarily when the recharging tank is removed from the inlet conduit. While pit crews are well-equipped to deal with inadvertent fires that may occasionally occur, there are immediate health risks to pit crew personnel other than the fire hazard. For example, modern racing engines are typically designed to have an effective compression ratio in excess of 10:1, and these high compression ratio engines require fuels having high octane ratings. Volatile anti-knock compounds such as tetraethyl lead and the like are formulated into racing fuels as octane boosters. Since these lead compounds are volatile and since they are known health hazards, the issue of inhalation of tetraethyl lead and related compounds as a health hazard to pit crews is a serious matter. In addition, any un-necessary release of raw hydrocarbon fuels into the atmosphere is a public health concern as well. While professional racing has enjoyed exemption from many regulations applicable to automobiles driven on public roads, there exists a need in the art to minimize fuel spillage, while maintaining the rapidity at which a fuel tank on a racing vehicle may be re-filled.
Another issue for automobiles is the concept of vapor lock. Vapor lock is a condition which is manifest by the pressure in the headspace above the fuel in an on-board fuel tank being lower than normal atmospheric pressure. Such a condition is caused to exist by virtue of the fuel pump removing fuel from the fuel tank, without the same volume of air being admitted into the tank to compensate for the lost volume of fuel because the fuel tank is sealed off from the atmosphere. Eventually, the fuel pump is required to pump fuel from an area of reduced pressure, and, not being designed for such use, a less-than-desired amount of fuel is delivered to the engine, which results in inhibited engine performance.